UMG and Sony Sue Suno Again, Challenging Its Licensed-Music v6 Model

Suno presented v6 as a licensed-music reset. Universal Music Group and Sony Music now say the new system is still built on an earlier model family whose training they allege used their recordings without permission, filing a second copyright lawsuit in Boston federal court.

The complaint adds more than 61,000 songs to the dispute. Its central claim is not that v6 directly used no licensed material, but that Suno developed it using outputs and user interactions from earlier systems—models UMG and Sony say were trained through unauthorized copying.

The training-data inheritance theory

The labels’ argument rests on how a newer model can learn from an older one. They allege Suno used knowledge distillation and related model-transfer techniques: a newer “student” model is trained to reproduce behavior learned by a preceding “teacher” model. In their view, that means v6 inherited the value of copyrighted recordings allegedly embedded in the earlier systems.

What the complaint says connects v6 to prior models

• Suno says v6 was trained exclusively on licensed music, according to the labels’ account of the company’s public position.
• UMG and Sony allege that v6 also learned from older-model outputs and from user interaction data, including preference signals.
• The labels contend that model-transfer methods do not remove the alleged value of recordings used to develop the older systems.

More than 61,000Songs added to the new dispute

The new complaint expands the legal fight by more than 61,000 songs.

Licenses and the market question

The suit also seeks to turn Suno’s recent licensing arrangements into evidence against the company’s legal position. UMG and Sony argue that Suno can no longer credibly say there is no market for AI training data when it is now paying to license music. The labels say that undercuts a key part of a fair-use defense, where harm to an existing market is a relevant consideration.

Their complaint reaches beyond model development. UMG and Sony allege that waves of AI-generated tracks are crowding streaming services, competing with human-made recordings and diminishing their value. Those are claims by the labels, not findings by a court.

A split inside the music business

The timing exposes a sharp industry divide. Warner Music Group was part of the original 2024 case against Suno, then settled and licensed its catalog to the company. UMG and Sony have continued litigating the earlier case while bringing this new one. Suno did not immediately respond to requests for comment on the latest complaint.

UMG and Sony’s core contention is that a licensing deal cannot make v6 a clean legal break from its predecessors. The case will test whether a newer AI model can be treated separately from the data, outputs and learned behavior that the labels say flowed into it from older models.